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Romeni S, Toni L, Artoni F, Micera S. Decoding electroencephalographic responses to visual stimuli compatible with electrical stimulation. APL Bioeng 2024; 8:026123. [PMID: 38894958 PMCID: PMC11184972 DOI: 10.1063/5.0195680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
Electrical stimulation of the visual nervous system could improve the quality of life of patients affected by acquired blindness by restoring some visual sensations, but requires careful optimization of stimulation parameters to produce useful perceptions. Neural correlates of elicited perceptions could be used for fast automatic optimization, with electroencephalography as a natural choice as it can be acquired non-invasively. Nonetheless, its low signal-to-noise ratio may hinder discrimination of similar visual patterns, preventing its use in the optimization of electrical stimulation. Our work investigates for the first time the discriminability of the electroencephalographic responses to visual stimuli compatible with electrical stimulation, employing a newly acquired dataset whose stimuli encompass the concurrent variation of several features, while neuroscience research tends to study the neural correlates of single visual features. We then performed above-chance single-trial decoding of multiple features of our newly crafted visual stimuli using relatively simple machine learning algorithms. A decoding scheme employing the information from multiple stimulus presentations was implemented, substantially improving our decoding performance, suggesting that such methods should be used systematically in future applications. The significance of the present work relies in the determination of which visual features can be decoded from electroencephalographic responses to electrical stimulation-compatible stimuli and at which granularity they can be discriminated. Our methods pave the way to using electroencephalographic correlates to optimize electrical stimulation parameters, thus increasing the effectiveness of current visual neuroprostheses.
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Affiliation(s)
| | | | - Fiorenzo Artoni
- Department of Clinical Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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2
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Slapø NB, Jørgensen KN, Elvsåshagen T, Nerland S, Roelfs D, Valstad M, Timpe CMF, Richard G, Beck D, Sæther LS, Frogner Werner MC, Lagerberg TV, Andreassen OA, Melle I, Agartz I, Westlye LT, Moberget T, Jönsson EG. Relationship between function and structure in the visual cortex in healthy individuals and in patients with severe mental disorders. Psychiatry Res Neuroimaging 2023; 332:111633. [PMID: 37028226 DOI: 10.1016/j.pscychresns.2023.111633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/12/2023] [Accepted: 03/17/2023] [Indexed: 04/09/2023]
Abstract
Patients with schizophrenia spectrum disorders (SCZspect) and bipolar disorders (BD) show impaired function in the primary visual cortex (V1), indicated by altered visual evoked potential (VEP). While the neural substrate for altered VEP in these patients remains elusive, altered V1 structure may play a role. One previous study found a positive relationship between the amplitude of the P100 component of the VEP and V1 surface area, but not V1 thickness, in a small sample of healthy individuals. Here, we aimed to replicate these findings in a larger healthy control (HC) sample (n = 307) and to examine the same relationship in patients with SCZspect (n = 30) or BD (n = 45). We also compared the mean P100 amplitude, V1 surface area and V1 thickness between controls and patients and found no significant group differences. In HC only, we found a significant positive P100-V1 surface area association, while there were no significant P100-V1 thickness relationships in HC, SCZspect or BD. Together, our results confirm previous findings of a positive P100-V1 surface area association in HC, whereas larger patient samples are needed to further clarify the function-structure relationship in V1 in SCZspect and BD.
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Affiliation(s)
- Nora Berz Slapø
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway.
| | - Kjetil Nordbø Jørgensen
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Psychiatry, Telemark Hospital, Skien, Norway
| | - Torbjørn Elvsåshagen
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Neurology, Oslo University Hospital, Norway
| | - Stener Nerland
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Daniel Roelfs
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway
| | - Mathias Valstad
- Department of Mental Disorders, Norwegian Institute of Public Health, Norway
| | - Clara M F Timpe
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Psychology, University of Oslo, Norway
| | | | - Dani Beck
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
| | | | | | - Trine Vik Lagerberg
- NORMENT, Division of Mental Health and Addiction, Oslo University hospital, Norway
| | - Ole A Andreassen
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; NORMENT, Division of Mental Health and Addiction, Oslo University hospital, Norway
| | - Ingrid Melle
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway
| | - Ingrid Agartz
- Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway; NORMENT, Division of Mental Health and Addiction, Oslo University hospital, Norway; Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Sciences, Stockholm Region, Stockholm, Sweden
| | - Lars T Westlye
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Psychology, University of Oslo, Norway
| | - Torgeir Moberget
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Department of Behavioral Sciences, Faculty of Health Sciences, Oslo Metropolitan University, OsloMet, Oslo, Norway
| | - Erik G Jönsson
- NORMENT, Institute of Clinical Medicine, University of Oslo, Norway; Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Sciences, Stockholm Region, Stockholm, Sweden
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3
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Khalaf A, Kronemer SI, Christison-Lagay K, Kwon H, Li J, Wu K, Blumenfeld H. Early neural activity changes associated with stimulus detection during visual conscious perception. Cereb Cortex 2023; 33:1347-1360. [PMID: 35446937 DOI: 10.1093/cercor/bhac140] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
The earliest cortical neural signals following consciously perceived visual stimuli in humans are poorly understood. Using intracranial electroencephalography, we investigated neural activity changes associated with the earliest stages of stimulus detection during visual conscious perception. Participants (N = 10; 1,693 electrode contacts) completed a continuous performance task where subjects were asked to press a button when they saw a target letter among a series of nontargets. Broadband gamma power (40-115 Hz) was analyzed as marker of cortical population neural activity. Regardless of target or nontarget letter type, we observed early gamma power changes within 30-180 ms from stimulus onset in a network including increases in bilateral occipital, fusiform, frontal (including frontal eye fields), and medial temporal cortex; increases in left lateral parietal-temporal cortex; and decreases in the right anterior medial occipital cortex. No significant differences were observed between target and nontarget stimuli until >180 ms post-stimulus, when we saw greater gamma power increases in left motor and premotor areas, suggesting a possible role in perceptual decision-making and/or motor responses with the right hand. The early gamma power findings support a broadly distributed cortical visual detection network that is engaged at early times tens of milliseconds after signal transduction from the retina.
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Affiliation(s)
- Aya Khalaf
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States.,Biomedical Engineering and Systems, Faculty of Engineering, Cairo University, Giza 12613, Egypt
| | - Sharif I Kronemer
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States.,Interdepartmental Neuroscience Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Kate Christison-Lagay
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Hunki Kwon
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Jiajia Li
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States.,School of Information & Control Engineering, Xian University of Architecture & Technology, Xi'an 710055, China
| | - Kun Wu
- Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States.,Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States.,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
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Qubad M, Barnes-Scheufler CV, Schaum M, Raspor E, Rösler L, Peters B, Schiweck C, Goebel R, Reif A, Bittner RA. Improved correspondence of fMRI visual field localizer data after cortex-based macroanatomical alignment. Sci Rep 2022; 12:14310. [PMID: 35995943 PMCID: PMC9395433 DOI: 10.1038/s41598-022-17909-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/02/2022] [Indexed: 11/30/2022] Open
Abstract
Studying the visual system with fMRI often requires using localizer paradigms to define regions of interest (ROIs). However, the considerable interindividual variability of the cerebral cortex represents a crucial confound for group-level analyses. Cortex-based alignment (CBA) techniques reliably reduce interindividual macroanatomical variability. Yet, their utility has not been assessed for visual field localizer paradigms, which map specific parts of the visual field within retinotopically organized visual areas. We evaluated CBA for an attention-enhanced visual field localizer, mapping homologous parts of each visual quadrant in 50 participants. We compared CBA with volume-based alignment and a surface-based analysis, which did not include macroanatomical alignment. CBA led to the strongest increase in the probability of activation overlap (up to 86%). At the group level, CBA led to the most consistent increase in ROI size while preserving vertical ROI symmetry. Overall, our results indicate that in addition to the increased signal-to-noise ratio of a surface-based analysis, macroanatomical alignment considerably improves statistical power. These findings confirm and extend the utility of CBA for the study of the visual system in the context of group analyses. CBA should be particularly relevant when studying neuropsychiatric disorders with abnormally increased interindividual macroanatomical variability.
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Affiliation(s)
- Mishal Qubad
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Catherine V Barnes-Scheufler
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Michael Schaum
- Leibniz Institute for Resilience Research, Mainz, Germany
| | - Eva Raspor
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Lara Rösler
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany.,Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Benjamin Peters
- Institute of Medical Psychology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany.,Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Carmen Schiweck
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Rainer Goebel
- Netherlands Institute for Neuroscience, Amsterdam, The Netherlands.,Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Andreas Reif
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Robert A Bittner
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy and Brain Imaging Center, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany. .,Ernst Strüngmann Institute for Neuroscience (ESI) in Cooperation With Max Planck Society, Frankfurt am Main, Germany.
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Shi C, Liu S, Zhao B, Meng Y, Gong X, Chen X, Tao L. Spatiotemporal Dynamics of Covert Attention With Different Degrees of Central Visual Field Defects: An ERP and sLORETA Study. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 35472216 PMCID: PMC9055563 DOI: 10.1167/iovs.63.4.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The present study aimed to investigate the spatiotemporal dynamics of covert attention by simulating different degrees of central visual field defects in healthy subjects. Methods An electroencephalogram (EEG) was recorded while 40 normal-sighted subjects performed a target discrimination task. Target stimuli simulated different defect degrees of the central visual field by artificially central scotomas (5, 10, 20, and 30 degrees of visual angle) masked on the center of black-and-white checkerboards. Event-related potentials (ERPs) and standardized low-resolution brain electromagnetic tomography (sLORETA) based on ERPs were analyzed. Results ERP results indicated that during early perceptual processes, compared with 5-degree and 10-degree defects, N1 amplitudes of 20-degree and 30-degree defects decreased, whereas P2 amplitudes significantly reduced in 30-degree defects. During later discrimination and decision processing, N2 amplitudes gradually increased from 5-degree to 30-degree defects, whereas P3 amplitudes gradually decreased. Source localization indicated that 5-degree and 10-degree defects had stronger activations than 20-degree and 30-degree defects from the occipital cortex to the ventral stream and dorsal streams. Especially, 30-degree defects primarily recruited additional activations in the ventrolateral prefrontal cortex and ventral stream and later caused the disconnection of dorsolateral prefrontal-posterior parietal cortices in the dorsal stream. Conclusions Different degrees of central visual field defects differed in distinct spatiotemporal characteristics at multiple stages of covert attention, from top-down forward feedback and attentional allocation to executive controls through ventral and dorsal processing streams, suggesting that the combination of ERP and source localization can reveal the spatiotemporal control capacity of the cortex on central visual field defects.
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Affiliation(s)
- Chaoqun Shi
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
| | - Sinan Liu
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
| | - Bingyang Zhao
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
| | - Yu Meng
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
| | - Xin Gong
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
| | - Xiping Chen
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
| | - Luyang Tao
- Department of Forensic Medicine, School of Basic Medicine and Biological Sciences, Affiliated Guangji Hospital, Soochow University, Suzhou, China
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Simar C, Petit R, Bozga N, Leroy A, Cebolla AM, Petieau M, Bontempi G, Cheron G. Riemannian classification of single-trial surface EEG and sources during checkerboard and navigational images in humans. PLoS One 2022; 17:e0262417. [PMID: 35030232 PMCID: PMC8759639 DOI: 10.1371/journal.pone.0262417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 12/23/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Different visual stimuli are classically used for triggering visual evoked potentials comprising well-defined components linked to the content of the displayed image. These evoked components result from the average of ongoing EEG signals in which additive and oscillatory mechanisms contribute to the component morphology. The evoked related potentials often resulted from a mixed situation (power variation and phase-locking) making basic and clinical interpretations difficult. Besides, the grand average methodology produced artificial constructs that do not reflect individual peculiarities. This motivated new approaches based on single-trial analysis as recently used in the brain-computer interface field. APPROACH We hypothesize that EEG signals may include specific information about the visual features of the displayed image and that such distinctive traits can be identified by state-of-the-art classification algorithms based on Riemannian geometry. The same classification algorithms are also applied to the dipole sources estimated by sLORETA. MAIN RESULTS AND SIGNIFICANCE We show that our classification pipeline can effectively discriminate between the display of different visual items (Checkerboard versus 3D navigational image) in single EEG trials throughout multiple subjects. The present methodology reaches a single-trial classification accuracy of about 84% and 93% for inter-subject and intra-subject classification respectively using surface EEG. Interestingly, we note that the classification algorithms trained on sLORETA sources estimation fail to generalize among multiple subjects (63%), which may be due to either the average head model used by sLORETA or the subsequent spatial filtering failing to extract discriminative information, but reach an intra-subject classification accuracy of 82%.
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Affiliation(s)
- Cédric Simar
- Machine Learning Group, Computer Science Department, Faculty of Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Robin Petit
- Machine Learning Group, Computer Science Department, Faculty of Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles- Vrije Universiteit Brussel, Brussels, Belgium
| | - Nichita Bozga
- Machine Learning Group, Computer Science Department, Faculty of Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Axelle Leroy
- Laboratory of Neurophysiology and Movement Biomechanics, Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Ana-Maria Cebolla
- Laboratory of Neurophysiology and Movement Biomechanics, Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Mathieu Petieau
- Laboratory of Neurophysiology and Movement Biomechanics, Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Gianluca Bontempi
- Machine Learning Group, Computer Science Department, Faculty of Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Guy Cheron
- Laboratory of Neurophysiology and Movement Biomechanics, Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Laboratory of Electrophysiology, Université de Mons-Hainaut, Mons, Belgium
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7
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Kwon H, Kronemer SI, Christison-Lagay KL, Khalaf A, Li J, Ding JZ, Freedman NC, Blumenfeld H. Early cortical signals in visual stimulus detection. Neuroimage 2021; 244:118608. [PMID: 34560270 DOI: 10.1016/j.neuroimage.2021.118608] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/19/2021] [Accepted: 09/20/2021] [Indexed: 11/16/2022] Open
Abstract
During visual conscious perception, the earliest responses linked to signal detection are little known. The current study aims to reveal the cortical neural activity changes in the earliest stages of conscious perception using recordings from intracranial electrodes. Epilepsy patients (N=158) were recruited from a multi-center collaboration and completed a visual word recall task. Broadband gamma activity (40-115Hz) was extracted with a band-pass filter and gamma power was calculated across subjects on a common brain surface. Our results show early gamma power increases within 0-50ms after stimulus onset in bilateral visual processing cortex, right frontal cortex (frontal eye fields, ventral medial/frontopolar, orbital frontal) and bilateral medial temporal cortex regardless of whether the word was later recalled. At the same early times, decreases were seen in the left rostral middle frontal gyrus. At later times after stimulus onset, gamma power changes developed in multiple cortical regions. These included sustained changes in visual and other association cortical networks, and transient decreases in the default mode network most prominently at 300-650ms. In agreement with prior work in this verbal memory task, we also saw greater increases in visual and medial temporal regions as well as prominent later (> 300ms) increases in left hemisphere language areas for recalled versus not recalled stimuli. These results suggest an early signal detection network in the frontal, medial temporal, and visual cortex is engaged at the earliest stages of conscious visual perception.
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Affiliation(s)
- Hunki Kwon
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA
| | - Sharif I Kronemer
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA; Interdepartmental Neuroscience Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Kate L Christison-Lagay
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA
| | - Aya Khalaf
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA; Biomedical Engineering and Systems, Faculty of Engineering, Cairo University, Giza, Egypt
| | - Jiajia Li
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA; School of Information and Control Engineering, Xian University of Architecture and Technology, Xi'an 710055, China
| | - Julia Z Ding
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA
| | - Noah C Freedman
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8018, USA; Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA.
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8
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Contactless measurements of retinal activity using optically pumped magnetometers. Neuroimage 2021; 243:118528. [PMID: 34464740 DOI: 10.1016/j.neuroimage.2021.118528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/20/2021] [Accepted: 08/27/2021] [Indexed: 11/23/2022] Open
Abstract
Optically pumped magnetometers (OPMs) have been adopted for the measurement of brain activity. Without the need to be cooled to cryogenic temperatures, an array of these sensors can be placed more flexibly, which allows for the recording of neuronal structures other than neocortex. Here we use eight OPM sensors to record human retinal activity following flash stimulation. We compare this magnetoretinographic (MRG) activity to the simultaneously recorded electroretinogram of the eight participants. The MRG shows the familiar flash-evoked potentials (a-wave and b-wave) and shares a highly significant amount of information with the electroretinogram (both in a simultaneous and separate measurement). We conclude that OPM sensors have the potential to become a contactless alternative to fiber electrodes for the measurement of retinal activity. Such a contactless solution can benefit both clinical and neuroscientific settings.
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Zeki S. "Multiplexing" cells of the visual cortex and the timing enigma of the binding problem. Eur J Neurosci 2020; 52:4684-4694. [PMID: 32722893 DOI: 10.1111/ejn.14921] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 07/11/2020] [Accepted: 07/19/2020] [Indexed: 12/01/2022]
Abstract
In this opinion essay, I address the perennial binding problem, that is to say of how independently processed visual attributes such as form, colour and motion are brought together to give us a unified and holistic picture of the visual world. A solution to this central issue in neurobiology remains as elusive as ever. No one knows today how it is implemented. The issue is not a new one and, though discussed most commonly in the context of the visual brain, it is not unique to it either. Karl Lashley summarized it well years ago when he wrote that a critical problem for brain studies is to understand how "the specialized areas of the cerebral cortex interact to provide the integration evident in thought and behaviour" (Lashley, 1931).
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Affiliation(s)
- Semir Zeki
- Laboratory of Neurobiology, Division of Cell & Developmental Biology, University College London, London, UK
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10
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Power L, Lalancette M, Bishop R, Beyea S, Taylor MJ, Dunkley BT, Bardouille T. Variability and bias between magnetoencephalography systems in localization of the primary visual cortex. Clin Neurol Neurosurg 2020; 194:105746. [PMID: 32217371 DOI: 10.1016/j.clineuro.2020.105746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 02/10/2020] [Accepted: 02/22/2020] [Indexed: 11/17/2022]
Abstract
OBJECTIVES When using MEG for pre-surgical mapping it is critically important that reliable estimates of functional locations, such as the primary visual cortex (V1) can be provided. Several different models of MEG systems exist, each with varying software and hardware configurations, and it is not currently known how the system type contributes to variability in V1 localization. PATIENTS AND METHODS In this study, participants underwent MEG sessions using two different systems (Vector View and CTF) during which they were presented with a repeating grating stimulus to the lower-left visual quadrant to generate a visual evoked field (VEF). The location, amplitude and latency of the VEF source was compared between systems for each participant. RESULTS No significant differences were found in latency and amplitude between systems, however, a significant bias in the latero-medial position of the localization was present. The median inter-system Euclidian distance between V1 localization across participants was 10.5 mm. CONCLUSIONS Overall, our results indicate that mapping of V1 can be reliably reproduced within approximately one centimetre by different MEG systems. SIGNIFICANCE This result provides knowledge of the useful limits on the reliability of localization which can be taken into consideration in clinical practice.
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Affiliation(s)
- Lindsey Power
- Biomedical Translational Imaging Centre (BIOTIC), IWK Health Centre, 5980 University Street, Halifax, NS, B3K 6R8, Canada.
| | - Marc Lalancette
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.
| | - Ronald Bishop
- Biomedical Translational Imaging Centre (BIOTIC), IWK Health Centre, 5980 University Street, Halifax, NS, B3K 6R8, Canada.
| | - Steven Beyea
- Biomedical Translational Imaging Centre (BIOTIC), IWK Health Centre, 5980 University Street, Halifax, NS, B3K 6R8, Canada; Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, NS, B3H 4R2, Canada; Department of Diagnostic Radiology, Dalhousie University, Room 319, Victoria Building, 1276 South Park St, Halifax, NS B3H 2Y9, Canada.
| | - Margot J Taylor
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.
| | - Benjamin T Dunkley
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada; Neurosciences & Mental Health, The Hospital for Sick Children Research Institute, Toronto, ON, Canada; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada.
| | - Timothy Bardouille
- Biomedical Translational Imaging Centre (BIOTIC), IWK Health Centre, 5980 University Street, Halifax, NS, B3K 6R8, Canada; Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, NS, B3H 4R2, Canada; Department of Diagnostic Radiology, Dalhousie University, Room 319, Victoria Building, 1276 South Park St, Halifax, NS B3H 2Y9, Canada.
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11
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Regev TI, Winawer J, Gerber EM, Knight RT, Deouell LY. Human posterior parietal cortex responds to visual stimuli as early as peristriate occipital cortex. Eur J Neurosci 2018; 48:3567-3582. [PMID: 30240547 PMCID: PMC6482330 DOI: 10.1111/ejn.14164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 08/24/2018] [Accepted: 09/07/2018] [Indexed: 11/30/2022]
Abstract
Much of what is known about the timing of visual processing in the brain is inferred from intracranial studies in monkeys, with human data limited to mainly noninvasive methods with lower spatial resolution. Here, we estimated visual onset latencies from electrocorticographic (ECoG) recordings in a patient who was implanted with 112 subdural electrodes, distributed across the posterior cortex of the right hemisphere, for presurgical evaluation of intractable epilepsy. Functional MRI prior to surgery was used to determine boundaries of visual areas. The patient was presented with images of objects from several categories. Event-related potentials (ERPs) were calculated across all categories excluding targets, and statistically reliable onset latencies were determined, using a bootstrapping procedure over the single trial baseline activity in individual electrodes. The distribution of onset latencies broadly reflected the known hierarchy of visual areas, with the earliest cortical responses in primary visual cortex, and higher areas showing later responses. A clear exception to this pattern was a robust, statistically reliable and spatially localized, very early response, on the bank of the posterior intraparietal sulcus (IPS). The response in the IPS started nearly simultaneously with responses detected in peristriate visual areas, around 60 ms poststimulus onset. Our results support the notion of early visual processing in the posterior parietal lobe, not respecting traditional hierarchies, and give direct evidence for onset times of visual responses across the human cortex.
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Affiliation(s)
- Tamar I. Regev
- Edmond and Lily Safra Center for Brain Science, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jonathan Winawer
- Department of Psychology, New York University, New York, New York, USA
| | - Edden M. Gerber
- Edmond and Lily Safra Center for Brain Science, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Robert T. Knight
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
| | - Leon Y. Deouell
- Edmond and Lily Safra Center for Brain Science, Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Psychology, Hebrew University of Jerusalem, Jerusalem, Israel
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12
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Parker A, Kember T, Dagnall N. Reduced effects of pictorial distinctiveness on false memory following dynamic visual noise. Memory 2016; 25:845-855. [PMID: 27637835 DOI: 10.1080/09658211.2016.1229793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
High levels of false recognition for non-presented items typically occur following exposure to lists of associated words. These false recognition effects can be reduced by making the studied items more distinctive by the presentation of pictures during encoding. One explanation of this is that during recognition, participants expect or attempt to retrieve distinctive pictorial information in order to evaluate the study status of the test item. If this involves the retrieval and use of visual imagery, then interfering with imagery processing should reduce the effectiveness of pictorial information in false memory reduction. In the current experiment, visual-imagery processing was disrupted at retrieval by the use of dynamic visual noise (DVN). It was found that effects of DVN dissociated true from false memory. Memory for studied words was not influenced by the presence of an interfering noise field. However, false memory was increased and the effects of picture-induced distinctiveness was eliminated. DVN also increased false recollection and remember responses to unstudied items.
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Affiliation(s)
- Andrew Parker
- a Department of Psychology , Manchester Metropolitan University , Manchester , UK
| | - Timothy Kember
- a Department of Psychology , Manchester Metropolitan University , Manchester , UK
| | - Neil Dagnall
- a Department of Psychology , Manchester Metropolitan University , Manchester , UK
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13
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Brief Report: Early VEPs to Pattern-Reversal in Adolescents and Adults with Autism. J Autism Dev Disord 2016; 46:3377-86. [DOI: 10.1007/s10803-016-2880-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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